Inventive concepts relate to a unit image sensor for compensating for light leakage, and more particularly, to a unit image sensor for reducing the influence of light of a long wavelength incident on a back side of the unit image sensor on a storage diode, and a method of compensating for light leakage in an image sensor array for removing a light leakage component left in the storage diode.
A global shutter image sensor circuit that has been recently introduced further includes a storage diode in addition to a conventional photodiode. According to a global shutter method, signals that are photoelectrically converted by all photodiodes in a single frame are transferred to a floating diffusion area at once and then output in units of lines that are sequentially selected. The single frame forms a single screen. It is assumed that, in a single frame, an image sensor circuit is formed of a plurality of lines that are serially connected.
With an increasing demand for a highly integrated circuit in which the size of an integrated circuit decreases but the number of image sensor circuits integrated in a limited area increases, a back side illumination method has been recently suggested. According to the back side illumination method, a total area forming a single electrode that forms a photodiode receives light that is externally input so that a low light performance is improved.